我的妹妹，最近刚刚作为女孩出道，却选择了我，她的哥哥，来练习性爱。两个对性知识还不甚了解的人之间的W失控活塞。
原标题: BLK-630 最近ギャルデビューをした妹がSEXの練習に選んだのが兄の僕。性の知識がまだあまりない二人のW暴走ピストン 倉本すみれ
A younger sister decides to become a gal. She decides to practice sex with me, her older brother! I'm the older brother, but I've never had any experience either... But I'll be embarrassed if I can't do it right when "the day" comes, and I have the dignity of an older brother, so we practice pistoning together! Maybe it's because we are related by blood, but our compatibility is superb! We are also genetically predisposed to be adulterous! They don't even realize they're coming, and even though they're both flowing backwards, they're still getting fucked by the runaway pistons of their brother and sister!
